Off the Pacific Coast of North America, rising postglacial sea levels have submerged a vast paleolandscape that almost certainly contains submerged terrestrial archaeological resources. Our proposed study will employ terrestrial analogues, paleoshoreline mapping, sediment coring, ground-trothing techniques, and biological assessments to test submerged geological landforms
that may contain cultural resources along the California Bight and off the central Oregon Coast and evaluate trophic subsidy near submerged features. Our proposed project relates to the Bureau of Ocean Energy Management's (BOEM) responsibility for monitoring and mitigating adverse impacts that might be associated with offshore energy development. This project addresses
potential socioeconomic impacts totese cultural and natural resources on the offshore continental shelf by evaluating the survey guidelines and avoidance criteria for biological resources and prehistoric archaeological and paleontological resources that may be adversely
affected by conventional or renewable energy development.
Goals and Objectives
• Improve models of submerged archeological resources by incorporating biological sampling data
• Quantify the trophic subsidy provided by relict hydrocarbon features to the benthic community, and explore the spatial extent of this subsidy and its effects on composition, abundance, and food web structure.
Logistics for field surveys will be coordinated between the co-Pis and vessel operators. Plans for fieldwork operations will be submitted to BOEM in advance of all efforts. For biological assessment, the spatial extent of the hydrocarbon subsidy will be quantified using stable isotope analysis of sediments and taxa from different trophic levels and feeding modes ( e.g. suspension
feeders, deposit feeders, carnivores). Stable isotope analysis can quantify the relative contributions of seep derived versus phytoplankton derived production to the benthic food web because the isotope values of these two sources of production are often we!! separated. The potential effect of the subsidy on community structure will also be evaluated. Sediment and
organisms will be collected along a distance gradient from the relict feature (e.g. at 1, 10, 100, and 500 m). Sediment and infaunal organisms will be collected using a box core. A total of 3-4 subcores will be taken and preserved in 10% formalin for community structure analysis. An additional 1-3 subcores will be sorted onboard to obtain specimens for stable isotope analysis.
These specimens and sediment samples will be immediately frozen on dry ice for transport to the laboratory at UCSB. Box core subsamples will be processed and preserved at sea and taxonomically sorted in the laboratory.
Field assistant: An SRA-level field assistant will coordinate shipboard sampling.
1. Sampling: Box cores will be used to sample benthic communities around submerged landforms including hydrocarbon seeps. Samples will be sorted and identified to species.
2. Communication: Results will be statistically analyzed and published in peer-reviewed journals. Miller will coordinate with Braje to facilitate quarterly and annual meetings, conference calls, agendas, and all reports ( quarterly, annual, final).
3, Data management:
• The following strategies will be implemented to manage, archive, and secure project data:
• Upon release of funding, we will secure and backup all fata on external hard drives and provide BOEM with a copy via hard drive at the conclusion of the project.
• All GIS-based products will include metadata documentation, as defined by the Federal Geographic Data Committee. Additional metadata requirements will meet BOEM Pacific Region standards.
• Digital deliverables will be delivered in electronic form to BOEM via a transfer
mechanism of mutual agreement.
• As part of final report submission, a subset of these data deliverables identified by BOEM and the Pis will be uploaded to the following public access map and data servers:
the National Geophysical Data Center (http://www.ngdc.noaa.gov/mgg/mggd.html) and
the NSF Marine Geoscience Data Center (http://www.marine-geo.org/index.php),' which is accessible to the GeoMapApp georeferenced data viewer
(http://www.geomapapp.org/). Any archaeologically sensitive information identified during this study will be provided to BOEM, but will not be uploaded to any public data servers.